Lamp unit



1952 E. B. NOEL ET AL 2,624,023

LAMP UNIT Filed Oct. 19, 1949 Flgz.

ITWVfilTOF'SI Edwavd B. NoeL,

PauL B.Davis, y W K His Al'."lTOT"heH.

Patented Dec. 30, 1952 2,624,023 LAMP UNIT Edward B. Noel, Cleveland Heights, and Paul B.

Davis, East Cleveland, Ohio, assignors to General Electric Company, a corporation of New York Application October 19, 1949, Serial No. 122,232

2 Claims.

The present invention relates to gaseous electric discharge lamps and particularly to such lamps capable of emitting a brilliant flash of actinic radiation useful in photography. Lamps of this type are known in the trade as fiashtubes and comprise a tubular vitreous container having an ionizable gaseous atmosphere therein, electrodes sealed into its ends and a triggering electrode engaging the outside of the envelope for facilitating the ignition of the lamp. Usually the tubular envelope is coiled helically but it may be of U-shape and it is the principal object of the present invention to provide a lamp unit including a fiashtube of U-shape and a simple, rugged mount for the flashtube and which mount may also serve as the triggering electrode. Further objects and advantages of the invention will appear from the following detailed description of species thereof and from the accompanying drawing in which, Fig. 1 is a perspective view taken from above the lamp unit including a U-shaped flashtube and a mount therefor, and Fig. 2 is a side elevational view of the lamp unit shown in Fig. 1 and showing a reflector for the flashtube in section.

Referring to the drawing, the flashtube of the lamp unit comprises a U-shaped vitreous envelope I having a cathode 2 sealed into one of its ends and an anode 3 sealed into the other end. The cathode 2 is mounted on a current inlead wire 4 passing through the end of the envelope l and the anode 3 is constituted by the inner end of a similar inlead wire 5. The envelope I has a filling of gas therein, preferably xenon, at a suitable pressure, such as 300 mm. The mount for the fiashtube comprises a base in the form of a disc 6 of electrically insulating material which has three spaced perforations I, 8, and 9 therein for accommodating screws or bolts by which the lamp unit may be attached to a suitable support. The plane including the envelope I is perpendicular to the plane of disc 6 and the envelope 1 is supported in this position mainly by one stifi metal wire support in which has two straight parallel portions l l and I2 offset from each other and connected by a bent portion l3. The part II of the wire ID extends between the legs I4 and of the U-shaped envelope l and two clamps I6 and [1 are welded thereto. The clamp 16 is in the form of a narrow metal strap welded to the free end of the wire l0 and encircles and engages the bent portion 18 of the U-shaped envelope I. The clamp I1 is also in the form of a strap welded to the part II of support wire l0 adjacent the curved portion l3 thereof, is transverse to the part II] and encircles and engages both legs [4 and of the U-shaped envelope 1 adjacent the electrodes 2 and 3. The end of part E2 of the support wire I0 is firmly attached to the disc 6 by a hollow electrical contact pin member I9 2 mechanically crimped on the disc 6 and into which the end portion of part I2 of the support wire is fastened by crimping, welding, or soldering.

The support wire l0 and its clamps l6 and I1 welded thereto are inside the part of the legs [4 and I5 enclosing the discharge path between the electrodes 2 and 3 except for the portion of the clamps around the envelope and therefore offer minimum obstruction to the passage of light from the flashtube. This is highly advantageous in securing a high utilization of light output with a minimum of shadow casting obstructions to the emitted light.

The lamp unit also comprises a pair of current lead wires 29 and 2! welded to the inleads 4 and 5, respectively. Said lead wires 29 and 2! are fastened to disc 6 by electrical contact pin numbers 22 and 23, respectively, which are of the same structure as pin it. The wires 20 and 2| are semi-rigid to give additional rigidity to the structure particularly against torsional forces. It is important, however, that the lead wires 20 and 21 have sufficient flexibility so that physical shocks to the equipment will not be transmitted to the glass surrounding the inleads 4 and 5. Such shocks tend to fracture the seal between the envelope 1 and the current inleads 4 and 5.

The lamp unit described above may be inserted in a suitable socket connected to a suitable power source for energizing the fiashtube. Such sources are commercially available and apply a high potential to the wire support It and its clamps l6 and ll which serve as a triggering electrode to ignite the flashtube. The wide spacing of the support wire it and the current leads 2c and 2| of the mount is advantageous in preventing fiashovers between the conducting elements of the unit outside the vitreous envelope 1. In order to increase the effectiveness of the wire support ii) and the clamps l6 and I! for igniting the fiashtube, a fine metal Wire 24 is wound around the fiashtube and electrically and physically connected to the clamps i5 and Il by wrapping its ends around the lower clamp IT and welding the turns thereto. The wire 24 rests against the clamp 16. When the flashtube does not require a triggering electrode, the wire 24 may be omitted with the power connection to the support wire Hi.

In Fig. 2 of the drawing, the lamp unit is illustrated with a metal reflector 25 of suitable shape, such as a parabolic reflector, mounted on the disc 6 by spinning the edge of the reflector 25 over the periphery of the disc 6 so that the disc is clamped within the reflector as shown. The lamp unit, with or without the reflector 2 5 may be inserted readily in a socket comprising spring fingers to grip the contact pins i9, 22 and 23. Obviously, leads from the power source may be soldered to the pins or the pins 19, 22 and 23 may 3 be omitted andtheipower leadssoldered directly to the leadsjfl and-2i and the support wire ill. When the pins 19 22 and 23 are omitted, staked eyelets may be used for fastening the support wire In and the lead wires 28 and 2| to the disc 6. Bolts passing through the openings 7, 8 and 9 may be used to fasten the disc 9 to a support ting ',gaseous "electric, discharge" lamphaving'e'lectrodes atv the endsthereoi, and a mounting and terminal structure therefor comprising a rigid disc-shaped base of insulating material adjacent to but-spaced from the ends of said la'mptin a plane transverse to the axis of the U-shaped lamp, a plurality of rigid terminal pins secured to -said discand extending outwardly therefrom on the side of the disc opposite said lamp, airigid conductive support wire anchored at one e'nd'to onelof s'aidterrninal pins and extending axially of said u shaped lampiand between the leg portions thereof to: .a point adjacent the bend of the U-shaped-lamp, a clamp member clamped around thesaid bend of the lamp and secured to, the adj aoent end ojf said support wire a second clamp member jsecured, to; an intermediate portion of said support wireandclamped around both legs of the U-shaped lamp adjacent the ends thereof, a triggering electrode wire encircling said lamp and electrically connected at its ends to the said s pport wire, and semi-rigid inlead wires connecting-theelectrodesat the ends of said lamp t respective terminal pins other than said one 9. 1 131 ;In combination, a .U -shaped light-trans- However 4 mitting gaseous electric discharge ,lamphavlng electrodes at the "ends thereof; andaamounting and terminal structure therefor comprising a rigid disc-shaped base of insulating material adjacent to but spaced from the ends of said lamp in a plane transverse to the axis of the U-shaped lamp, a plurality of rigid ternnnal pins secured to saiddisc in a triangular pattern at widely'spa'ce'd points about the center of the disc and extending outwardly therefrom on the side of the disc opposite said lamp, a rigid conductive support-wire anchored at one end to one of said terminal pins and extending, in part, normally to the disc at the center of the disc and axially of said U-shaped lamp and between the leg portions thereof to a pointadja'cent the bend of'the U -shaped lamp,"aclamp memberclamped around: the said bend 'ofthe lamp and secured were adjacent end of said support-wire, a-second clamp member secured to an intermediate portion of said support wire andclamped aroundboth'legs' of the U -shaped lamp adjacentthe ends thereof, a triggering electrode wire encircling said lamp and electrically connected at its 'ends'to'the'tsaid support wire, and semi-:rigid inlead wires "extending from the ends of the lamp in a direction gen erallyaway fromsaid support Wire and-connecting the electrodes at the ends of saidrlamp to respective terminal pins other than said one'pin.

EDWARD B. NOEL. PAULB. DAVIS.

REFERENCES CITED The following references are of remrdiittne file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,020,736 Pirani Nov.-12;;1935 2,171,580 Macksoud Sept; 5, 1939 2,264,092 McCauley Nov. 25,1941 2,277,697 Grier Man-31, 1942 2,399,222 Germeshausen Apr.-30, 1946" 2,467,472 Goshorn Apr. 19, 1949 2,491,881 Van Liempt Dec. 20, 1949 

